A small wooden cross memorializing a murdered Minneapolis teenager has mysteriously appeared 57 years later at the exact spot along a Minneapolis park path where her body was abandoned in the snow.

Mary Louise Bell’s niece happened upon the modest memorial Saturday as she and an aunt were walking their dogs on the tree-lined dirt trail in Minnehaha Park.

Erica Bell said that while on the walk, she was telling her aunt about this being the park where Mary Bell was found slain, when suddenly they stumbled directly upon the site.

“There was this little white cross with her name on it, and it was like, whoa,’ ” Erica Bell said. “It was a big shock to see it there. I stood there for a little while with my aunt.”

Mary Bell’s niece was born nearly 13 years after the killing but knew the story well of Mary Bell’s death at the hands of her sister’s boyfriend, Ronald Steeves. She immediately recognized the significance of the date painted in red on the white cross standing slightly akilter amid the leaves.

Now Erica Bell’s father, one of Mary’s five siblings, is on a mission to find out who put the cross there — and why.

John Bell said a cascade of emotions washed over him when his daughter showed him a photo of what she discovered on a route that is not among her usual dog-walking destinations.

“I was floored, and obviously, I was surprised,” said the 68-year-old Minneapolis Park and Recreation Board retiree, who was 11 when his sister was killed. “And then I was inquisitive, thinking, who? Ronnie Steeves’ family, out of a sense of guilt? No one in my family would do that.”

Regina Catholic High School sophomore Mary Bell had attended Ash Wednesday services and then was babysitting when the 19-year-old Steeves lured her out for a ride, then repeatedly stabbed and bludgeoned her.

The 15-year-old’s body was found the next day, Feb. 28, 1963, by a park employee next to the path near Minnehaha Falls, setting off news coverage of one of the Twin Cities’ more sensational crimes of that time.

According to court documents and newspaper reports, Steeves killed Bell because he feared she would tell that he was dating her older sister Patricia over the strict objections of their father. He was tried within a few months, convicted of first-degree murder and sentenced to life in prison. Parole was an option back then with a life sentence, and Steeves was freed after 20 years. Within months, he was picked up on a rape allegation and died by suicide in January 1984 in the Ramsey County jail.

After his daughter’s weekend discovery, John Bell posted a photo of the cross on a Nextdoor neighborhood web page and on the Regina High School Facebook page along with an explanation of its significance to him and his family.

“No, no clues,” he said since reaching out to his fellow Standish neighborhood residents and Regina alums. “Just sympathies and people remembering.”

Among those who remember Bell’s murder vividly is Stephen Crawford, who was 7 years old and lived in the Bells’ neighborhood at the time.

“It had a great effect on me,” said Crawford, a historian for his own family who about 10 years ago used his ancestral digging skills to build a page on findagrave.com with background of Bell’s death and a brief biography. “I never witnessed a crime like that in my life.”

John Bell knew of the page’s existence and got in touch with Crawford for the first time. Now the two are teaming up on their mission to answer the “who” and “why” behind the cross, which was adorned in time for Holy Week with what resembles a crown of thorns.

Crawford said he has never sought out the spot where Mary Bell’s body was found but would visit the park often over the years, as recently as last week while out for a run.

“Anytime I am in that park, you feel a certain sadness,” he said. “I imagine other people feel the same way [that] such a horrible thing happened in that beautiful park.”

Crawford surmises that someone who was alive back in 1963 placed the cross there “and just felt they needed to.”

About 5 miles to the southeast of that spot on the park path, Mary Bell is buried in the family plot in Resurrection Cemetery in Mendota Heights along with her father and other family members.

John Bell swings by every so often, mows the grass and cleans the headstones.

But Bell never has visited — and says he never will — that patch of dirt where his sister’s body was abandoned many decades ago.

“I wouldn’t go down there,” he said. “I’ve worked hard to heal from all those traumas, but now it’s time to let her back in my life again.”